Well tool coupling device



Feb. 13, 1962 D. Q. HOOKS 3,021,160

WELL TOOL COUPLING DEVICE Filed June 12, 1959 2 Sheets-Sheet 1 INVENTOR. :DONALD Q. Ho oms Feb. 13, 1962 p, oo s 3,021,160

WELL TOOL COUPLING DEVICE Filed June 12, 1959 2 Sheets-Sheet 2 INVENTOR. "DONALD Q. HooK ATTORNEY-S 3,021,160 WELL TOOL CUUPLKNG DEVHCE Donald Q. Hooks, 20S Frisco St., Henderson, Tex. Filed June 12, 1959, Ser. No. 820,948 3 Claims. (Cl. 2%7-119) The present invention relates to well tools generally and in particular to a releasable coupling device whereby a sucker rod may be disconnected from or connected to a pump plunger within the well so that the sucker rod and tubing may be separately removed.

In the maintenance of a well, either oil or water, it is frequently desirable to withdraw from a well the tubing string in which a pump plunger and sucker rod are positioned. Due to the size of the pump plunger relative to the well tubing, it is frequently difficult to withdraw from the well the sucker rod and pump plunger attached thereto and it is advantageous to be able to disconnect the sucker An object of the present invention is to provide a coupling device for coupling a sucker rod to a pump plunger or other well tool, which device is readily attached to and detached from the sucker rod and pump plunger, and one which is readily separable when in the well so that the sucker rod may be withdrawn from the well leaving the pump plunger therein.

Another object of the present invention is to provide a coupling device for a well tool which is sturdy in construction, one easily and readily assembled by a relatively unskilled person, one which is positive in operation, one having few parts which lend themselves to manufacture in quantity at reasonable cost, and one which is highly effective in action.

These and other objects and advantages of the present invention will be fully apparent from the following description when taken in conjunction with the annexed drawings, in which:

FIGURE 1 is a sectional view through a length of well tubing showing the coupling device of the present invention attached to the lower end portion of a sucker rod and attached to the upper end portion of a pump plunger or other well tool, the coupling being shown in disconnected condition;

FIGURE 2 is a view similar to FIGURE 1 with the coupling in connected condition;

FIGURE 3 is a sectional view showing the coupling in position prior to disconnecting of the upper and lower coupling members from each other; and

FIGURE 4 is an exploded isometric view of the coupling device of the present invention, shown removed from the tubing and disconnected from the sucker rod and pump plunger.

Referring in greater detail to the drawings in which like numerals indicate like parts throughout the several views, in FIGURES 1 to 3, the reference numeral 1t designates generally a section of well tubing in which is a pump plunger 12, only the portion of the latter adjacent the upper end being shown. The lower end portion of a sucker rod 14 is shown in FIGURES 1 to 3 and it is normally connected to the upper end portion of the plunger 12 for reciprocating the plunger 12.

The device of the present invention is designated generally by the reference numeral 16 and comprises a lower coupling member 18 and an upper coupling member 29.

3,@Zl,lii Patented Pei). 13, 1952 The lower coupling member 18 includes a base 22 having means for securing the member 18 to the plunger 12, such means embodying a socket 24 extending inwardly from the lower end thereof and threadedly receiving the upper end portion of the plunger 12. A mandrel 26 constituting a wedging means projects from the upper end of the base 22. The mandrel 26 flares from the lower end to the upper end and carries on its upper end a male element or tongue 28 arranged axially with respect to the mandrel 26. The portion of the member 18 between the base 22 amid the mandrel 26 is provided with a shoulder 3% below which is cut a groove 32 in which is seated 0 ring 34. l

The upper coupling member 20 includes means for securing the member 20 to the sucker rod 14, such means embodying a head 36 having a threaded end portion 38 threadedly received within a bore 4% provided in the lower end of the sucker rod 14. A tubular extension 42, having an open lower end projects axially from the lower end of the head 36.

The portion 44 of the inner wall of the extension 42, adjacent the lower end, tapers outwardly from the lower end to the upper end of the portion 44. The tapered wall portion 44 constitutes another wedgi-ng means.

The mandrel 26 is freely insertable into and withdrawable out of the extension 42 through the lower end of the extension 42 and when in the fully inserted position, the extension 42 is spaced from the tapering wall portion 44.

Wedging means is normally positioned within the space between the tapering wall portion 44 and the mandrel 26 when the latter is within the extension 42 and is connected to the extension 42 for movement toward and away from the member 25). Such wedging means consists in a plurality of semicylindrically shaped slips or plate elements 46 dependingly carried by a ring 48 which is positioned within the extension 42 transversely thereof and spaced above the tapering wall portion 4-4. The slips or elements 46 are arranged so as to form a slotted cylinder, as shown most clearly in FIGURE 4, each of the elements 46 being movable toward and away from the mandrel 26 independently of each of the other elements 46. The ring 48 is connected to the extension 42 for upward and downward movement.

Spring means is provided operatively connected to the ring 48 for urging the latter to its downward movement position, such means embodying a coil spring 50 positioned between the ring 48 and the lower end of the head 36.

Means is provided operatively connected to the wedging means or elements as for shifting the elements 46 from the position in the space between the mandrel 26 and the wall portion 44 when the mandrel 26 is within the extension 42 to a position above the wall portion 44 to permit withdrawal of the mandrel 26 from the extension 42. This means consists in a screw member 52 having a female element or slot 54 projecting inwardly from the head 56 thereof. The portion of the shank 58 of the screw member 52 adjacent the end remote from the head 56 is threadedly engaged in a bore 66 which extends inwardly from the lower end of the upper coupling member head 36 and terminates at a point spaced from the lower end of the head 36. The slot 54 in the screw member head 56 is conformably shaped to loosely receive therein the tongue 28 on the upper end of the mandrel 26.

The lower end portion of the extension 42 is provided,

adjacent the lower end of the wall portion 44, with a shoulder 62 against which abuts the shoulder 3i! on the lower coupling member 18 when the latter is positioned so that the mandrel 26 is fully inserted into the extension 42.

In operation, the plunger 12 with the lower coupling member 18 secured thereon is first lowered into the well. When it is desired to attach thereto the sucker rod 14, the upper coupling member 26 is attached to the lower end of the sucker rod 14 and is lowered into the well so that the mandrel 26 enters into the lower open end of the extension 42. Upon insertion of the mandrel 26 into the lower open end of the extension 42, the shoulder portion 64 of the mandrel 25 engages the lower end of the wedging elements as and pushes them upwardly against the compression of the spring 59 and spreads them apart sufficiently that the mandrel 26 enters freely into the wall portion 44. This is accomplished by dropping the sucker rod 14 with the attached upper coupling member 20. When the mandrel 26 is fully inserted into the extension 42, the spring 50 pushing on the ring 48 drives the elements 46 back into the space between the mandrel 26 and the tapered wall portion 44 of the extension 42 and into wedging engagement with the mandrel 26 so that the mandrel 26 cannot be pulled outwardly from the lower end of the extension 42.

Normally, the coupling member 18 and coupling member 20, when the latter members are in locked position, are rotatable relative to each other, although in normal operation of the pumpattached to the lower end of the plunger 12 there is no rotation of the coupling members relative to each other.

When it is desired to remove the sucker rod 14 from the well, the uncoupling of the coupling members 18 and 20 from each other is accomplished by first lowering the Weight of all the attached sucker rods 14 into the well so that their combined weights force the extension 42 toward the lower coupling member base 22 which permits relative rotation of the sucker rod 14 with respect to the plunger 12, the latter being bound by the connection of the pump on the lower end of the plunger 12 to the well casing, neither the pump nor the wall casing being shown. The sucker rod 14 is then caused to rotate in one direction so that the engagement of the tongue 28 in the slot 54 prevents rotation of the screw member 52 relative to the upper coupling member head 36. This results in screwing of the screw member 52 upwardly in the bore 60 carrying with it the ring 48 and the com pressed spring 50 and efiecting the withdrawal of the wedging elements 46 from their position between the mandrel 26 and the wall portion 44 to the position above the wall portion 44 and out of working engagement with the mandrel 26.

With the screw member 52 raised in the bore 60, the mandrel 26 may be withdrawn through the open lower end of the extension 42 and the sucker rod 14 withdrawn from the tubing to the ground surface.

When it is desired to attach the upper coupling member to the lower coupling member 18, a special tool is employed to unscrew the screw member 52 outwardly of the bore 60 to its original position in which the upper portion of the head 56 engages the ring 48 and operatively connects the screw member 52 to the wedging elements 46 for eifecting their upward movement from the normal position adjacent the wall portion 44 to the above position.

What is claimed is:

1. For use with a well tubing including a pump plunger positioned within said tubing, and a sucker rod positioned within said tubing and spaced above said plunger, a coupling device for securing said sucker rod to said plunger, said device comprising a lower coupling member having the lower end provided with means for securing said coupling member to said plunger, an upper coupling member having the upper end provided with means for securing said upper coupling member to said sucker rod, a first wedging means embodying a plurality of slips connected to the lower end of said upper coupling member for movement toward and away from said upper coupling member, a cooperating second wedging means embodying a flared mandrel on said lower coupling member, the coupling device further including means connect ing said upper coupling member to said lower coupling member so that said first wedging means is moved into wedging engagement with said second wedging means responsive to the movement of said first wedging means away from said upper coupling member and said first wedging means is moved out of wedging engagement with said second wedging means responsive to execution of the movement of said first wedging means toward said upper couplin member, spring means operatively connected to said first wedging means urging the latter to the away movement position, said means embodying a female element on said upper coupling member interengaging cooperating means embodying a male element on said lower coupling member when said first wedging means is in the away movement position and operable to shift said first wedge means to the toward movement position re sponsive to rotary movement of said upper coupling member relative to said lower coupling member.

2. For use with a well tubing including a pump plunger positioned within said tubing, and a sucker rod positioned within said tubing and spaced above said plunger, a coupling device for securing said sucker rod to said plunger, said device comprising a lower coupling member having the lower end provided with means for securing said coupling member to said plunger, an upper coupling member having the upper end provided with means for securing said upper coupling member to said sucker rod, a first wedging means connected to the lower end of said upper coupling member for movement toward and away from said upper coupling member, a cooperating second wedging means on said lower coupling member, means connecting said upper coupling member to said lower coupling member so that said first wedging means is moved into wedging engagement with said second wedging means responsive to the movement of said first wedging means away from said upper coupling member and said first wedging means is moved out of wedging engagement with said second wedging means responsive to execution of the movement of said first wedging means toward said upper coupling member, and means on said upper coupling member interengaging cooperating means on said lower coupling member when said first wedging means is in the away movement position and operable to shift said first wedging means to the toward movement position responsive to rotary movement of said upper coupling member relative to said lower coupling member.

3. For use with a well tubing including a pump plunger positioned within said tubing, and a sucker rod positioned within said tubing and spaced above said plunger, a coupling device for securing said sucker rod to said plunger, said device comprising a lower coupling member having the lower end provided with means for securing said coupling member to said plunger, an upper coupling member having the upper end provided with means for securing said upper coupling member to said sucker rod, a first wedging means connected to the lower end of said upper coupling member for movement toward and away from said upper coupling member, a cooperating second wedging means on said lower coupling member, means connecting said upper coupling member to said lower coupling member so that said first wedging means is moved into wedging engagement with said second wedging means responsive to the movement of said first wedging means away from said upper coupling member and said first wedging means is moved out of wedging engagement with said second wedging means responsive to execution of the movement of said first wedging means toward said upper coupling member, and

6 means embodying a female element on said upper cou- References Cited in the file of this patent pling member inter-engaging cooperating means embody- UNITED STATES PATENTS ing a male element on said lower coupling member when said first wedging means is in the away movement posi- 1,327,188 BPTgeSS 13, 1931 tion and operable to shift said first Wedging means to th 5 1,849,101 LlVefgOOd r- 15, 93 toward movement position responsive to rotary movement 2,244,714 Livergood June 10; 1941 of said upper coupling member relative to said lower 2,921,634 Bloudoif Jan. 19, 1960 coupling member. 

